Agenda
28 May 2027
16:00
Helmholtz Lecture Lauri Nummenmaa: Imaging the whole-body emotion circuits with total-body positron emission tomography
University of Turku, Finland
| Abstract: Emotions are intimately linked with the homeostatic control of the body. Although modern neuroimaging techniques allow quantification of neuronal changes associated with higher mental processes such as emotion and cognition, these are typically investigated independently of the physiological state of the body because conventional imaging techniques (e.g. MRI and MEG) do not allow simultaneous functional imaging across multiple tissues. The major advantage of positron emission tomography (PET) is that the acquisition of the projection data is not limited by physical or electronic properties. Instead, the limits arise from the counting statistics of coincident photon detection, as in conventional PET scanners a roughly 85%–90% of the body always is outside the FOV of the scanner and even within the FOV, less than 5% of the gamma rays can be collected, as the radiation is emitted isotopically thus not intercepting the detector rings. Total-body PET resolves both these problems by extending the detector rings so that they cover practically the whole body. The axial field of view of our Siemens Quadra PET camera is 106 cm which is about four times longer than the axial field of view in the current PET/CT scanners. It covers the whole-body from head to approximately mid-thigh in a single scan in subjects/patients and an estimated 24-fold increase in head to-thigh scan and 4-fold increased for single tissue/organ studies. With modern total-body PET scanners yielding ultrasensitive sub-second total-body imaging we can investigate the neurobiology and peripheral physiology of human mental functions simultaneously. In this talk I present and overview of the recent methodological developments in total-body PET in the context of affective neuroscience, with special focus on the automated kinetic modelling, preprocessing, and spatial normalization approaches developed at the Turku PET Centre. I then describe how our work using total-body PET with radioligand [15O]H2O and pharmacological (isoprenaline, adenosine) as well as sensory and psychological (cold stressor, emotional movies) emotion models have revealed the interacting emotion circuits across the brain and the periphery. Finally, I discuss how the total-body imaging will lead to a paradigm shift in our understanding of the biological circuits underlying human mental functions. |
